1. Field of the Invention
This invention relates to photographic camera apparatus, and, more particularly, to photographic camera apparatus of the type including an independent eye level viewfinder and a reflex through-the-lens focusing system for providing a magnified image of part of the camera's field of view.
2. Description of the Prior Art
Presently available self-processable type film units, because of their nature, generally have relatively large picture areas with format diagonals exceeding three of more inches. Examples of film units which may have such formats are described in detail in, for instance, U.S. Pat. No. 2,983,606 issued to H. G. Rogers on May 9, 1961 and entitled "Products and Products for Forming Photographic Images in Color" and U.S. Pat. No. 3,415,644 issued to E. H. Land on Dec. 10, 1968 and entitled "Novel Photographic Products and Processes".
Because of these large formats and the need for a resonable field of view, cameras suitable for use with such film units tends to be large in proportion to the film size. Moreover, suitable viewing and ranging apparatus associated with such cameras tend to add to their overall size. However, there are a number of prior art patents which disclose single-lens reflex type cameras that are relatively compact in size in spite of being suitable for use with the larger film format.
One such camera, which folds into a thin compact shape that will fit into a garment pocket, is described in U.S. Pat. No. 3,678,831 issued to James G. Baker on July 25, 1972 and entitled "Compact Folding Reflex Camera". Examples of other folding cameras which employ the camera's objective taking lens as a component of these viewing and focusing arrangements are described in detail in U.S. Pat. No. 3,003,407 issued to D. S. Grey on Oct. 10, 1961 and entitled "Combined Range Finder and View Finder" and U.S. Pat. No. 2,914,997 issued also to D. S. Grey on Dec. 1, 1959 and entitled "Combined Range and View Finder". Examples of non-folding single-lens reflex type cameras are described in, for example, U.S. Pat. No. 3,958,257 issued to Bruce K. Johnson on May 18, 1976 and entitled "Compact Reflex Box Camera", U.S. Pat. No. 3,760,704 issued to James G. Baker on Sept. 25, 1973 and entitled "Reflex Camera and Viewer with Folded Optical Path", U.S. Pat. No. 3,800,309 issued to Edwin H. Land on Mar. 16, 1974 and entitled "Exposure, Viewing and Focusing System" , and U.S. Pat. No. 3,672,281 issued to Edwin H. Land on June 27, 1972 and entitled "Reflex Camera".
In each of the foregoing patents, the camera's objective taking lens is employed as part of the viewfinder to provide a "through-the-lens" view of the subject matter which the objective taking lens will image on the film unit. In addition, the camera's taking lens is employed as part of the focusing arrangement such that a camera user may observe an image formed by the objective taking lens to adjust the objective taking lens for sharp focus.
While each of the viewing and focusing arrangements of these disclosures are perfectly satisfactory for the functions they perform, they tend to achieve compactness by using either a relatively large number of optical components or optical components which are relatively complex in nature. Despite these relative complexities, these reflex type cameras have certain viewing and ranging advantages because of the parallax free view they provide of the image formed by the camera's objective taking lens.
In addition to reflex type cameras with through-the-lens viewing and focusing capability, the prior art proposes combined eye level type view and range finders which function independently of the camera's objective taking lens. Examples of this type are described, for example, in U.S. Pat. No. 3,221,627 issued to H. A. Bing et. al. on Dec. 7, 1965 and entitled "Photographic Range and Viewfinder", and U.S. Pat. No. 3,581,644 issued to Philip G. Baker et al. on June 1, 1971 and entitled "Combined Viewfinder-Rangefinder". These disclosures utilize a simple viewing and framing system with a coincidence type ranging device coupled with the focusing movement of the camera's objective taking lens. The viewing system could also be a simple optical device such as a reversed Galilean telescope.
The primary advantage of these systems resides in the simplicity of the viewer. Their primary disadvantage, however, lies in the ranging device which requires maintaining precise manufacturing tolerances for greatest accuracy and the added complication of requiring a linkage which couples the rangefinder to the focusing movement of the camera's objective taking lens. One variation of this type system is disclosed in U.S. Pat. No. 2,632,357 issued to J. Mihalyi on Mar. 24, 1953 and entitled "Combined Range and View Finder". The patentee, in this disclosure, proposes an optical arrangement which provides a magnified part image of the viewing field, independent of the objective taking lens, for purposes of facilitating ranging. This arrangement, however, also has the disadvantages previously referred to in connection with the combined eye level type view and range finder system. Consequently, there is a need in the art for a viewing and ranging system which combines the merits of through-the-lens ranging and the simplicity of viewing independently of a camera's objective taking lens. It is therefore a primary object of the present invention to fulfill this need. Another object of this invention is to provide simplified viewing and focusing apparatus for use with cameras which utilize large format self-processable type film units.
Another object of the present invention is to provide simplified viewing apparatus which functions independently of a camera's objective taking lens in combination with through-the-lens focusing apparatus which uses only part of the image formed by a camera's objective taking lens for purposes of focusing.
Other objects of the invention will in part be obvious and will in part appear hereinafter. The invention accordingly comprises the apparatus possessing the construction, combination of elements and arrangement of parts which are exemplified in the following detailed disclosure.